1. Technical Field
The present invention relates to a method for controlling light-emission of a light-emitting diode (LED) light source, and more particularly, to a method for controlling light-emission of an LED light source by adjusting a heat-dissipation power of a thermal module in real time.
2. Description of Related Art
With the development of the photoelectric industry, there has been a trend to replace conventional light sources with LEDs, but the light power of LEDs must be increased and kept stable to meet practical needs. However, heat is generated and accumulated when an LED is turned on for a long time, resulting in a higher junction temperature and a lower luminous efficacy of the LED. As a result, light power of the LED will continue to decrease and cannot be maintained stable.
In order to stabilize the light power of LEDs, a variety of optical sensors, temperature sensors, voltage sensors, etc. have been incorporated into LED light source driving modules, so as to drive and monitor the LEDs in real time, thereby maintaining the light power of the LEDs.
For example, U.S. Pat. No. 7,132,805 uses a temperature sensor, a current waveform sensor and a voltage differential sensor to monitor working characteristics, such as a working temperature, a working current, etc., of an LED and adjust an input current in real time, so as to maintain the light power of the LEDs.
In addition, U.S. Patent Published Application No. 2006/0022614 A1 uses a color optical sensor and a temperature sensor for monitoring an illumination color and a working temperature of LEDs in real time, respectively. The LEDs can be disposed on a heat-dissipation device and combined with a feedback mechanism, allowing a heat-dissipation power of the heat-dissipation device to be adjusted as the temperature sensor monitors the working temperature of the LEDs in real time. Therefore, heat generated by the LEDs can be dissipated in real time to maintain light power of the LEDs.
However, the aforementioned LED light source driving modules must work with various optical sensors, temperature sensors, voltage sensors and so on, which not only complicate structures of the LED light source driving modules, but also significantly increase their production costs. Moreover, the control methods employed are also very complicated.